This is the viral moment with over a million views a vigilante bus passenger karate-kicks an apparently drunk man in the face and sends him flying.

The incident happened on a number 16 bus in the city of Ezhou in Central China’s Hubei Province on 17th February and police are now investigating after began going viral after it was shared online.

The passenger, who witnesses said was drunk, began arguing with the bus driver and can be heard insulting him after apparently being made to run after the vehicle.

In the video, the allegedly belligerent passenger does not one strike the bus driver despite his threatening tone, and he appears to begin walking away to find a seat when the attack takes place.

The viral footage shows him turning towards the aisle when the burly vigilante commuter plants a flying kick to his face.

The forceful kick sends the drunkard’s head jerking backwards before he collapses backwards into the metal stairwell next to the front door.

The attacker, who appears to stamp on the downed commuter for good measure, is pulled away by other passengers.

Ezhou authorities said they will summon both passengers as well as the driver for questioning.

A series of violent bus-related incidents have been highlighted in China ever since a bus carrying 15 including its driver plunged off a bridge into a river, killing 13 and leaving two still unaccounted for.

The crash was triggered by an argument between the driver and one of his passengers.